Over the next few days, an active weather pattern will continue to drive a plume of Pacific precipitation into the Northwestern United States of America.
Rainfall in the Northwest
Rainfall amounts ranging from heavy to excessive will be at risk, mostly along with Washington and northern Oregon coastlines, where the Weather Prediction Center has issued a Slight Risk for heavy to extreme rainfall on Friday.
Between now and then, enough cold air will flood into the Pacific Northwest and Northern/Central Rockies to prepare the foundation for considerable snowfall in the higher terrain, measured in feet, in the coming days.
In addition, accumulations of snow and ice are anticipated in the lower elevations of eastern Washington into Friday morning.
Throughout most of the Pacific Northwest, winter storm warnings and advisories are in force.
Because of a low-pressure system moving into eastern Canada, substantial lake effect snow is expected to fall when cool westerly winds blow over the still comparatively warm waters of the lakes.
Snow Forecast in the Midwest
Favorable spots downwind of the lakes may get 6 to 12 inches of snow by Saturday morning, with greater amounts possible in certain areas. Arctic air will rush farther south and east behind the cold front associated with this storm, finally reaching the Great Plains and the Midwest by Friday.
Sub-zero daytime highs will blanket the northern Plains today, while temperatures as much as 20-25 degrees below normal will blanket the Central Plains, sections of the southern Plains, and eastward into the Midwest and Ohio Valley on Friday, according to the National Weather Service.
As the Arctic front moves into the Deep South, a wave of low pressure is expected to form along its path.
Cold Weather and Snowfall in the Northeast
It is possible to see a light snowfall to the north of the front from Kansas into Missouri, where a couple of inches of snow are predicted to fall.
A significant amount of snow is anticipated to fall in sections of Tennessee Valley and the Central Appalachians today, with some ice predicted to form farther south across areas of southern/eastern Tennessee and northern Mississippi and Alabama as the low moves across the region.
In this location, the combination of snow and ice may result in severe driving conditions through tonight and into tomorrow.
As the low-pressure system moves off the Mid-Atlantic coast Friday morning and swiftly intensifies offshore, accumulating snow will also expand into the Mid-Atlantic and Northeast, where a few inches of snow are expected in certain locations.
Larger quantities may be realized throughout eastern areas of New England, but the precise amounts are still unknown and greatly dependant on the precise course of the low-pressure system off the coast.
Warnings and advisories for winter storms are in force for most of the Tennessee Valley, the Central Appalachians, and the Mid-Atlantic region. As it prepares to leave, a low-pressure system will cause modest lake effect snow across the Lower Great Lakes while also creating strong winds throughout most of the Northeast.